Device for copying on polishing or brushing machines for hollow articles

ABSTRACT

A polishing and brushing machine having a cross-slide arrangement adapted to receive workpieces thereon for moving same relative to a polishing wheel. The movement of the workpiece is automatically controlled by means of a template mounted on the machine frame, which template coacts with a switching stylus mounted on the cross-slide for controlling the movement thereof. The template permits selective polishing of the entire workpiece or of the edge areas.

United States Patent [721 Inventors Karl Eugene Becker Geislingen; Karl Oberlander, Geislingen; Hugo Fessler, Geislingen; Kurt Jager, Miesbach, all of, Germany [211 App]. No, 764,893

[22] Filed Oct. 3, 1968 [45] Patented July 27, 1971 [7 3] Assignee Wurttembergische Metallwarenfabrik Geislingen Steige, Germany [32] Priority Oct. 4, 1967 [33] Germany [54] DEVICE FOR COPYING ON POLISHING OR BRUSHING MACHINES FOR HOLLOW ARTICLES 3 Claims, 9 Drawing Figs. 7

[52] U.S.Cl 51/100 [51] Int. Cl B24b 17/06,

B24b 9/00 [50] Field of Search 51/100,

127,165.05; l5/2lC.3

[56] References Cited UNITED STATES PATENTS 2,675,652 4/l954 Chiappulini 51/100 3,290,829 12/1966 Martin et al. 51/100 3,324,493 6/1967 Kraft 15/21 (C.3) 3,439,371 4/1969 Kraft 51/100 X Primary Examiner-Othell M. Simpson AttorneyWoodhams, Blanchard and Flynn ABSTRACT: A polishing and brushing machine having a cross-slide arrangement adapted to receive workpieces thereon for moving same relative to a polishing wheel. The movement of the workpiece is automatically controlled by means of a template mounted on the machine frame, which template coacts with a switching stylus mounted on the crossslide for controlling the movement thereof. The template permits selective polishing of the entire workpiece or of the edge areas.

70 D)?! V[ FOR LOWER SLIDE PATENTEflJuLensn SHEET U 0F 5 Fig.7

DEVICE FOR COPYING ON POLISHING R BRUSHING MACHINES FOR HOLLOW ARTICLES The invention relates to a device for the progressive pass copying of the edge and total surface area of hollow articles, such as trays or basins, on polishing or brushing machines in which the workpiece is mounted on an automatically controlled cross table, of which one slide can be longitudinally displaced in stages after stopping an electric switch tracer or stylus, actuated by a contour control template and connected to said cross table, and the second slide of which can be transversely displaced, after the longitudinal feed pass of the first slide is performed by a reversible feed device, until the switch stylus is in contact with the template in which case either the control template is multisectional in design together with a central portion which can be moved out of the tracer path or the electric switch stylus cooperating with the contour control template is provided with a control device which actuates the longitudinal and transverse feed motions every time or only after every second time that the tracer is in contact with one o the control cams.

This device enables the edge zone of the workpiece to be machined more frequently and therefore more intensively than its surface. The mode of operation is advantageous when compared with brushing or polishing machines which only' permit machining of the entire workpiece with a uniform intensity. However the described device does not obtain the results or produce the quality which can be achieved by manual machining. It is impossible to machine several specific parts of the workpiece, in order to remove, for example, flaws which may occur when such workpieces are produced without cutting.

In accordance with a previous proposal a brushing or polishing machine is so designed that the workpiece is mounted on a cross table, the slide movements being controlled manually. Specific machining of the surface may thereby be achieved, but this polishing machine has the disadvantage that it must be operated by a skilled expert. Production costs and time are thereby substantially increased.

The aim of the invention is to provide an elaboration of the kind of device initially described so that, despite automatic control, it enables controlled machining of the workpiece corresponding to the design of the workpiece and producing results comparable with good manual work.

The problem is solved in accordance with the invention because, in addition to the contour control device, a programmable control device giving commands to the slide drives controlled by the contour control device, is provided for the selective repetition of individual or several related feed movements, said commands predominantly overlapping the commandsof the contour control device.

The programmable control device permits the machining of a series of uniform hollow articles, produced by the same tools, by automatic means but with a controlled intensity, as was hitherto only possible when machining by hand. Any desired point on the workpiece can be passed over as often as desired by the tool. Flaws which are caused during the manufacture of each workpiece of such a series can thus be compensated in an efficient manner. Furthermore, the control device permits a rapid change of program when workpieces of extremely like shape, but having carrying flaws or differing surface quality are machined.

The copying or tracing device equipped with the control device in accordance with the invention thereby provides a superioror higher grade end product by means of a more efficient mode of operation.

The control device advantageously has arrangements for initiatingauxiliary functions, such as abrasive feed, turning of workpieces, disengaging of tools, pivoting of the polishing units, etc. The entire machining operation is thus fully automatically controlled. In this connection the control of the auxiliary functions can be advantageously adapted to the operating program with maximum accuracy. A considerable amount mand repetitions of the slide movements or to control auxiliaof readjustment would be required if the operation was only controlled by a contour control device, whereas a single program is sufiicient in the case of the inventive device combined with the control device. The control device therefore causes a further reduction in the operating time normally required by a skilled operator and at the same time increases the quality of the workpiece.

The control device is advantageously coupled by basically known switch members operating subject to time or travel to one of the two slides or to the displaced portion of the contour control device. The switch members inform the control device simply about the progress of the operation which is directed as before by the contour control device. They therefore enable the control device to influence the course of the operation at the programmed points, for example, to comry functions.

The switch members may consist advantageously of cam arrangements and end switches actuated thereby. The cams arranged at intervals subject to the travel generate pulses which continuously control the control device.

The cams are advantageously mounted on the lower slide and the associated end switches are so designed that they control the reversing movement of the lower slide. The cam arrangement and the end switches thereby fulfill a double function since they control the reversing movement of the slide and take over the continuous control of the control device. The reversing movement of the slide is thus ensured without any additional device even if the control device is not engaged in the operation.

Alternatively, the switch members may consist of a time relay and a stepping switch connected thereto. The program continues to be controlled in this way subject to time.

Furthermore, the control device can be coupled to a time relay for reversing the movement of the slide, in which case the arrangement of associated cams mounted on the slide is rendered superfluous. The control device advantageously has a punched card control. When a program is changed, only the replacement of the punched card or a punched tape is necessary.

Embodiments of the invention are shown in the drawing.

FIG. 1- shows a side view of a polishing machine for hollow articles equipped with a device in accordance with the invention;

FIG. 2 is a front view of the polishing machine shown in FIG. 1;

FIG. 3 shows a schematic plan view of the outline tracing template of a first embodiment of the device according to the invention;

FIG. 4 shows a cross section through the tracing template corresponding to the line 0-0 in FIG. 3 and having an associated switch stylus;

FIG. 5 shows a side view of the template in the direction of the arrow R shown in FIG. 3;

FIG. 6 shows a top view on to the outline tracing template of a second embodiment of the device according to the invention;

FIG. 7 shows a cross section through the template along the line 8-8 shown in FIG. 6, and through a switch stylus,

FIG. 8 is an enlarged illustration of the cam strip with trigger cams and limit switches at the undertable in a front view, and

FIG. 9 is a side view of the cam strip and limit switches shown in FIG. 8.

In FIGS. 1 and 2 reference numeral 1 generally designates a polishing machine having four stations. The machine has a base frame 2 which bears a cross table arrangement 3 and, above the stands 4, a polishing assembly 5 having four polishing units 6. The polishing assembly 5 can be pivoted by means of hydraulic work units 7 which are installed in the stands 4. Each polishing unit 6 has a polishing wheel 8 and can be pivoted by an adjustable cylinder 9, as shown on a polishing unit in FIG. 2.

The cross table 3 comprises a lower slide 10, which can travel on railsll, and an upper slide I2 which runs on rails 13 perpendicular to the rails l I. The upper slide I2 supports four workpiece holders I4, the workpieces being hollow articles, and a holder 15 for a vertical tracing template. The lower slide I is driven by a hydraulic work unit I6, and the upper slide 12 likewise by a hydraulic work unit 16.

The vertical movement of the polishing assembly is effected by a tracer or stylus 17 attached thereto which cooperates with the vertical tracing template and controls the work units 7 so that, when the workpieces, i.e. the hollow articles, are moved by the cross table 3, the polishing wheels 8 follow the vertical profiles of said workpieces.

The movement of the cross table is controlled by a contour control device, generally designated by the reference numeral 18, combined with a cam arrangement having the corresponding end switches or a time relay, or by a control device 19 which can be programmed with punched cards. In this way the contour control device efiects an operation wherein the edge zone of the workpiece is machined more frequently than its surface as will be explained in the description of the operation. The programmed control device 19 intervenes through the line connection 40 (FIGS. 1 and 2) at specific stages in the operation and, by repeating several related slide movements, brings about more intensive machining at particular points on the tool. Furthermore, subject to the course of the operation, the device 19 controls several auxiliary functions which will be explained in detail later.

' An embodiment of a contour control device 18 is shown in detail in FIGS. 3 to 5. In these Figures reference numeral 20 designates an outline control template which comprises two symmetrically designed and disposed outer portions 21a and 21b and a central portion 22. The outer portions 21a and 21b are provided with control curves 21c and 21d whereas the central portion 22 has a control curve 22a surrounding it. The control curves 21c and 21d correspond to the outer contour of the edge of the workpiece, the tray-shaped hollow article, while the control curve 22a corresponds to the inner contour of said edge.

The central portion 22 can be lowered from the operating position shown by unbroken lines in FIG. 4 into an inoperative position 22' shown by broken lines in the same Figure. In the case of the illustrated embodiment the central portion 22 is mounted on one end of a two-armed lever 23 which can be pivoted about a rocker bearing 25 by means of a drive 24 engaging on the opposite end of said lever. The direction in which the drive 24 moves is indicated by a double arrow P in FIG. 5.

A switch stylus 26 (FIG. 4) cooperates with the control template 20, can be moved in the direction of a double arrow A and is rigidly connected to the cross table by an arm 27 (FIGS. 1 and 2). The switch stylus 26 controls the drives for both slides 10,12 of the cross table 3 through lines 41, 42 and 43 schematically illustrated in FIGS. 1 and 2.

U.S. Pat. No. 3,439,371, assigned to the same assignee as the present invention, illustrates one of many possible examples of an electromechanical circuit which may be utilized to accomplish the desired result and reference is to be made thereto.

To polish the edge zone of the workpiece three times and the remaining surface area twice, the cross table arrangement 3 is controlled by means of the outline control template 20 in the following manner;

First the central portion 22 of the control template 20 is located in the raised operating position by corresponding actuation of the drive 24. In FIG. 3 the switch stylus commences its travel at I. The transverse feed is actuated by switching on the machine, i.e. the upper slide 112 is driven, and passes, together with the workpiece holders l4 and the workpieces, the hollow articles, below the polishing wheels 8. The switch stylus 26 performs the same movement relative to the control template 20 and comes into contact with the control curve 21d at II. The switch operation actuated thereby-causes the drive of the upper slide 12to be reversed and the drive of the lower slide 10 to be actuated, the latter being in operation for a fixed distance or for a specific constant time so that that the workpieces as well as the stylus 26 perform a longitudinal step from I] to III. By reversing the drive the upper slide 12 moves back until the stylus meets the control curve 21c at IV. There the drive of the upper slide is again reversed and a longitudinal feed pass is actuated. However, when the stylus 26 moves back, it'meets the control curve 22a of the central portion 22 at V so that a longitudinal step and a reversing movement are performed at this point. The stylus 26 thereby performs the progressive pass feeding movement shown by an unbroken line L in FIG. 3 between the control curves 21c and 22a until, at VII in FIG. 8,-it reaches an end switch which causes the longitudinal feed to be reversed. The polishing wheels 8 execute the same progressive pass feeding movement over the edges of the workpieces. After the longitudinal feed is reversed, the

stylus 26 and the polishing wheels 8 are passed back along the opposite edge of the workpiece by the progressive pass feed until the starting portion I is reached. The edge of the workpiece is thereby subjected to a single polishing operation.

The central portion 22 is then lowered into the position 22' by means of the drive 24 and the two-armed lever 23. It is thereby moved out of the area wherein the stylus 26 moves. The latter commences its movement again at I and passes through the positions II, III, and IV to V. However, the stylus does not strike against the control curve 22a lowered in the meantime, at this point, but passes on until it meets the control curve 21d at VI. Not until this point is reached is the next longitudinal feed and reverse pass initiated. As a result the stylus 26 oscillates back and forth on a meanderlike course between the control curves 21c and 21d. Also this movement is reversed by the last switch cam (VII, FIG. 8) and the corresponding end switch until the starting position is again reached. Therefore, the polishing wheels 8 performing a corresponding movement pass twice over the entire workpiece including the edge zones. Where this path does not intersect the path L, it is represented by broken lines in FIG. 3 and designated by K.

The tracing control device as shown in FIGS. 6 and 7 has an outline tracing template 28 in which two symmetrical curved recesses or cavities 29a and 291) are produced. Their sidewalls form outline control curves 30ad. A stylus 31 cooperates with the template 28 and is connected to a switch mechanism 32. The switch mechanism 32 is designed in known fashion so that, in its first switch position, it emits a control pulse upon every lateral deflection of the stylus 31, whereas in its second switch position it only gives off a control pulse with every second deflection of the stylus. These pulses in turn control the drive of the upper and lower slides 12, 10 of the cross table arrangement 3.

In order that the polishing wheels 8 can pass over the edge zones of the workpieces three times and over the entire surface area of said workpieces twice, theswitch mechanism 32 is now brought into its first switch position. The stylus 31 therefore runs back and forth on a meanderlike course between the control curves 30a and 30b or 30c and 30d until it has covered the entire edge zone once. Then the switch mechanism 32 is shifted into the second switch position. Since the switch mechanism 32 is now only emitting a pulse with every second deflection of the stylus, the inner control curves 30b and 300 have beenrendered inoperative. The switch stylus then meanders back and forth between the outer control curves 30a and 30b thereby passing over theentire workpiece. The course of movement is shown in detail as precise as in FIG. 3. Therefore, only the two curves L and K are indicated in FIG. 6.

The lower slide 10 is connected by a support 33 to a cam plate 34 on which cams 35 are disposed. The earns 35 cooperate with end switches 36 which are supported on the base frame 2 by means of a support 37. The end switches 36 effect the reversing movements of the slides and are controlled by the cams 35 to correspond with the movement of the lower slide 10, i.e. subject to the distance to be covered.

At the same time the end switches 36, being actuated by the earns 34, pass electric pulses to the control device 19 through the line 44 (FIG. 2), schematically illustrated, whereupon the latter continues to be controlled. In accordance with its program the control device 19 passes commands to the end switches through line 45 (FIG. 2), schematically illustrated, which commands predominantly overlap those of the stylus 26 or 31. The control device 19 can thereby repeat any slide movement as often as desired, as well as any desired sequence of several slide movements. For, example, such a command of the control device can cause the movement of the workpiece shown in FIG. 3 to be repeated three times along the curve L from the point M as far as the point N, or the movement of the workpiece along the line M0 on the curve K can be repeated once. Furthermore, the control device can effect a movement of the the workpiece relative to the tool, as indicated by the dotted line curve R in FIG. 3.

Moreover, the control device 19 has unshown switch mechanisms which are controlled by punched cards and switch an auxiliary function of the polishing machine on or off. Amongst these auxiliary functions are included the feeding of abrasives, the turning of workpieces by an unshown mechanism, the disengaging of tools by pivoting the polishing units by means of the adjustable cylinders 9. After the entire program is completed, the control device returns the upper slide 12 and, therefore, the outline control device to the starting position.

The invention is not restricted to the exemplary embodiment. Instead of a cam arrangement and end switches coupled thereto, the connection between the lower slide and the control device may also consist of a time relay and a stepping switch mechanism. In this case the control device can also control the reversal of the slides via a second time relay.

The cam arrangement may be attached to the upper slide or the stylus instead of to the lower slide and may cooperate with end switches disposed in a corresponding position.

The control device may also have a programmable magnetic control in place of a punched card control.

All the features shown in the specification and the drawings together with the constructional details may also be essential to the invention in other combinations.

We claim 1. An apparatus for the brushing or polishing of a workpiece, comprising:

a frame;

a polishing tool rotatably mounted on said frame;

cross-slide means movably mounted on said frame and including first and second slide means movable relative to said tool, said second slide means being movable in a direction substantially transverse to the direction of movement of said first slide means;

first drive means for causing reeiprocatory movement of said first slide means;

second drive means for causing reeiprocatory movement of said second slide means;

mounting means on said cross-slide means for mounting said workpiece thereon;

contour control means for controlling the motion of said cross-slide means and of the workpiece mounted thereon relative to said tool, said contour control means including template means mounted on one of said cross-slide means and said frame and a template follower mounted on the other of said cross-slide means and said frame, said template means having cam contours thereon substantially corresponding to the outline of said workpiece and said template follower being adapted to contact said cam contours;

supplementary control means for selectively controlling said first and second drive means for permitting selected treatment of said workpiece by said tool, said supplementary control means overriding and dominating said contour control means; and switching means operatively connected to said supplementary control means and said contour control means and responsive to the movement of said cross-slide means to control the motion of said workpiece relative to said tool in addition to the control of said motion by said contour control means and said supplementary control means.

2. A-machine according to claim 1, wherein said switching means comprises a plurality of cams fixedly connected to one of said frame and said cross-slide means and a plurality of end switches, actuatable by said plurality of cams, mounted on the other of said cross-slide means and said frame.

3. A machine according to claim 2, wherein said plurality of cams is mounted on said first slide means and the plurality of end switches are mounted on said frame to control the motion of said first slide means. 

1. An apparatus for the brushing or polishing of a workpiece, comprising: a frame; a polishing tool rotatably mounted on said frame; cross-slide means movably mounted on said frame and including first and second slide means movable relative to said tool, said second slide means being movable in a direction substantially transverse to the direction of movement of said first slide means; first drive means for causing reciprocatory movement of said first slide means; second drive means for causing reciprocatory movement of said second slide means; mounting means on said cross-slide means for mounting said workpiece thereon; contour control means for controlling the motion of said crossslide means and of the workpiece mounted thereon relative to said tool, said contour control means including template means mounted on one of said cross-slide means and said frame and a template follower mounted on the other of said cross-slide means and said frame, said template means having cam contours thereon substantially corresponding to the outline of said workpiece and said template follower being adapted to contact said cam contours; supplementary control means for selectively controlling said first and second drive means for permitting selected treatment of said workpiece by said tool, said supplementary control means overriding and dominating said contour control means; and switching means operatively connected to said supplementary control means and said contour control means and responsive to the movement of said cross-slide means to control the motion of said workpiece relative to said tool in addition to the control of said motion by said contour control means and said supplementary control means.
 2. A machine according to claim 1, wherein said switching means comprises a plurality of cams fixedly connected to one of said frame and said cross-slide means and a plurality of end switches, actuatable by said plurality of cams, mounted on the other of said cross-slide means and said frame.
 3. A machine according to claim 2, wherein said plurality of cams is mounted on said first slide means and the plurality of end switches are mounted on said frame to control the motion of said first slide means. 